Don't know about the FTS's, Martin, but Superdomes are lousy in my rifles, regardless of caliber. Sorry! One hole groups with Kodiaks, need a dinner plate to catch the 'Domes.
I've had Simmons 44 Mags on both of mine, but I just got a Hawke 4-16x50 MAP Pro to try out. Put it on last night, still have some tweeking to do, but I'm liking it. Will post more info when I've had a chance to really wring it out. Had one of the Center Points, good scope for the money and a good match to the TSS, gave it to my brother for his when I got my second 44 Mag. Had a lower power NS Nighteater for awhile on my last springer, okay, but I don't think I'd buy another, especially if this Hawke pans out as well as I think it's going to.
Can't help you with the micro meter tank, although I can throttle my Blodnob valve back enough to duplicate one. If you're looking for a low power indoor setup, I'd go there before CO2. But you can turn the stock TSS down a lot too, I'm currently running my stock tank with only a .035" TH setting and PW at 1 or 2. With an 18" barrel that's still giving me around 900 fps with CPL's. A 12" barrel would probably be around 750 or so, maybe less. Just a couple more days, now, hang in there :-). Later.
Dave